1. Technical Field
The present invention relates to a liquid ejecting head, a liquid ejecting apparatus, a piezoelectric element, and an ultrasonic sensor.
2. Related Art
In the related art, a liquid ejecting head which ejects droplets from a nozzle which communicates with a pressure generating chamber by generating a pressure fluctuation in liquid in the pressure generating chamber by transforming a piezoelectric element has been known. As a representative example thereof, there is an ink jet recording head which ejects ink droplets as droplets.
The ink jet recording head includes, for example, a piezoelectric element on one surface side of a flow path forming substrate on which the pressure generating chamber which communicates with nozzle openings is provided, and ejects ink droplets from nozzles by generating a pressure fluctuation in the pressure generating chamber by transforming a vibrating plate using a drive of the piezoelectric element.
Such a piezoelectric element is configured of a first electrode which is provided on the vibrating plate, a piezoelectric layer, and a second electrode (for example, refer to JP-A-2009-172878).
When making density of a piezoelectric element high according to high density of nozzle openings, the thickness or an area of the piezoelectric element becomes small, and an electric capacitance increases. The increase in the electric capacitance leads to an increase in a calorific value of the piezoelectric element, and accordingly, there is a problem in that a performance of the piezoelectric element deteriorates due to the heat generation.
In addition, there are problems in that a performance of an ultrasonic sensor using the piezoelectric element also deteriorates due to the heat generation, and an ink ejecting performance in an ink jet recording head using the piezoelectric element also deteriorates due to the heat generation. In addition, such a problem exists not only in the ink jet recording head, also in a liquid ejecting head which ejects liquid other than ink.